/vt/ - Virtual Youtubers

What even are voice packs?
Are they just random noises vtubers make that people can use for notification noises? Full blown audio dramas where you pretend to go on a date with them? Something else entirely?

My voice is probably my strongest asset and I'd like to showcase via something similar, but in addition to not really knowing what they're all about I also don't know where the bar rests in terms of quality and production for these sorts of things.